orcaflex 9.6a


orcaflex 9.6a

The slam area used for slam force calculation was not very reasonable for a hollow spar buoy or towed fish whose axis was not normal to the surface. Previously the slam area was always the waterplane intersection area of the cylinder annulus, but for a hollow buoy hitting with its axis parallel to the water surface it is much more reasonable to use slam area equal to the waterplane intersection area of the whole cylinder (outer diameter).

OrcaFlex spreadsheet

The OrcaFlex spreadsheet is now compatible with Office 2013.
Bug fixes

Previous versions of OrcaFlex contained a very subtle bug affecting dynamic simulations using the implicit solver. The problem only occurred when connections were released during the simulation. For example, consider a model with a calculated vessel and three lines attached. If, during the simulation, one of the lines was released, then the OrcaFlex system solver could, under certain circumstances, incorrectly associate solver degrees of freedom with the line nodes. This almost always resulted in the simulation failing due to unstabilty.
Modal analysis for a model with no lines results in an Access Violation error.
The command to export SHEAR7 modes file from a batch script was erroneously reporting that the modes file cannot be generated for lines that included torsion. This was a limitation in older versions, but was lifted in version 9.6a. However, the block on modes file export for such lines was not removed from the batch script code.
The equal-and-opposite reaction force applied to the splined line in a line contact relationship could be applied at an incorrect node. This issue could only arise if the penetrating node position was exactly at the boundary between two splined line segments.
Importing Newman QTFs from WAMIT .out files, into a vessel type which had radians as its phase unit, could result in incorrect values for some QTFs.
In some circumstances, importing full QTFs from AQWA files could fail with an obscure error message. The import procedure has been corrected, and if it does fail (for some other reason) it will at least give a helpful explanation.
The point of application of the slam force on a hollow cylinder (non-zero inner diameter) of a spar buoy or towed fish was being mis-calculated. This problem only applied to hollow spar buoys or towed fish, and has now been fixed.
The modal analysis calculation was incorrectly accounting for flex joint stiffness. The effect of attached Flex Joints was included twice, and modal analysis stiffness was therefore lower than the user intended. This error affects modal analysis results, and therefore any cases where Shear7 or VIVA have been used via OrcaFlex. Dynamic analysis behaviour and results are not affected.

These bugs are fixed in version 9.6c.
New in version 9.6b
Modal Analysis

Modal analysis results now include the loads associated with each calculated mode shape. These mode loads are reported in both tabular and graphical form.

The OrcaFlex interface to SHEAR7 now supports SHEAR7 version 4.7.
User interface

Workspace files, with .wrk extension, can now be applied by dragging them onto the main OrcaFlex window.
Bug fixes

On some machines, but not all, attempts to use shaded graphics fail with a floating point exception.
The program could, in rare circumstances, report access violation errors when a dynamic simulation fails due to instability.
Some fatigue data files using the text YAML format cannot be loaded. This bug only affects files that contained empty lists. For example, empty S-N curve lists, empty load case lists, empty analysis data, etc.
The ExtendSimulation batch script command leads to a floating point error when executed on a model in the reset state. This command is only meaningful when a simulation is active and so the fix is for the program to report a more appropriate error.
Enabling the Show Trails option on the replay form, whilst a custom replay is playing, leads to an access violation.
The line selection drop down list on the SHEAR7 data form does not function correctly. It always displays the first line in the model in spite of any attempts to change the value.
In version 9.6a only, there is a flaw in the way the mode offset distribution and mode type is calculated for lines that include torsion. The weighting given to the rotational offsets in the mode, and hence the offset distribution percentages and mode type, depends on the segment lengths used to model the line.

These bugs are fixed in version 9.6b.
New in version 9.6a
64 bit OrcaFlex

Version 9.6 now includes 64 bit versions of the OrcaFlex executables. 32 bit versions of the executables are still included and are fully supported.

The 64 bit version runs slightly quicker than the 32 bit version. However, the main benefit is that the 64 bit version can access more memory than the 32 bit version. This is especially significant for machines with a very large number of processors.

The installation package copies both 32 and 64 bit versions of the executables, even on a 32 bit system. On a 32 bit system, the shortcuts and file associations are configured to execute the 32 bit version. On a 64 bit system, the shortcuts and file associations are configured to execute the 64 bit version. If you wish to run the 32 bit version on a 64 bit system, you will need to create an appropriate shortcut - the installation program will not do so. The 32 bit executable is named OrcaFlex.exe and the 64 bit executable is named OrcaFlex64.exe.

The OrcaFlex spreadsheet is now compatible with 64 bit versions of Excel. The installation process will detect which version of Excel is installed, and register the OrcaFlex add-in with that version of Excel. Post-processing using the OrcaFlex spreadsheet from the batch form is supported no matter which combination of OrcaFlex and Excel you are using. For example, if you are running 64 bit OrcaFlex and have 32 bit Excel installed, the OrcaFlex spreadsheet can still be processed from the batch form.

Native external functions will need to be re-compiled as 64 bit DLLs in order to work with 64 bit OrcaFlex. More generally, if you need your external function to work with both 32 and 64 bit versions of OrcaFlex, then you need to compile two separate versions, a 32 bit version and a 64 bit version. These should be located in the same directory and the 64 bit version given the suffix of 64. For example, if the 32 bit external function DLL is named ExtFn.dll then the 64 bit DLL must be named ExtFn64.dll. If you follow this naming convention, then OrcaFlex will load whichever external function DLL matches the architecture of the OrcaFlex process. Please refer to the OrcFxAPI help file for full details.

Python external functions are fully supported under 64 bit OrcaFlex. Note that you must install a 64 bit version of Python to use Python external functions from 64 bit OrcaFlex. Likewise, to use Python external functions from 32 bit OrcaFlex, you must install a 32 bit version of Python. Multiple Python versions can be installed on a single machine so it is perfectly possible to use Python external functions from both 32 and 64 bit versions of OrcaFlex on a single machine.

All OrcaFlex automation capabilities are fully supported for both 32 and 64 bit. The OrcaFlex DLL, OrcFxAPI, is available in both 32 and 64 bit versions. The different versions of the DLL are both named OrcFxAPI.dll. The installation program installs binary files (.dll, .lib) to OrcFxAPIWin32 and OrcFxAPIWin64 respectively. Previous versions of OrcaFlex also installed OrcFxAPI.dll to the Windows system directory. Starting with version 9.6, OrcFxAPI.dll is no longer installed to the Windows system directory. Please refer to the OrcFxAPI help file for details of how to link to OrcFxAPI.dll.

The Python and MATLAB interfaces to OrcaFlex now support both 32 and 64 bit versions of OrcaFlex. To use 64 bit OrcaFlex from Python or MATLAB you need to install a 64 bit version of Python or MATLAB. We will continue to support these interfaces in both 32 and 64 bit forms. So if you have already installed 32 bit Python or MATLAB then you are perfectly at liberty to continue using the 32 bit versions. In fact, not all 3rd party modules are easy to obtain for 64 bit Python so there may be situations where it is preferable to use 32 bit Python.

In order to export videos from 64 bit OrcaFlex using the XVID codec, you must have the 64 bit version of the codec installed. The latest versions of the XVID codec install both 32 and 64 bit versions. However, if you installed XVID from an older installation package, then you may only have the 32 bit version of the codec installed. Installing the latest version, from http://xvid.org, will resolve the problem.

The OrcaFlex interface to VIVA is the only part of the program that is not currently supported in the 64 bit version of OrcaFlex. The reason for this is that the VIVA interface is implemented as an in-process DLL. That DLL is only available in 32 bit format. We intend to address this issue in a future release by implementing the VIVA interface in a different manner. In a future release we will use the VIVA executable files instead of the VIVA DLL. This will have the added benefit that the interface will keep pace with any developments to VIVA - the VIVA DLL is currently lagging behind mainstream VIVA. In the meantime, you will need to use the 32 bit version of OrcaFlex in order to gain access to the interface to VIVA.
New Line Contact Model

You can now model contact between lines using a new Line Contact model. This new contact model is particularly suitable for modelling systems where:

One line (or more than one) is inside another line, such as pipe-in-pipe systems and pull-in operations.
One or more lines are constrained to follow another line at certain arc lengths, such as choke and kill lines on drilling risers, installation guide wires and piggy-back risers.
A line strikes the outer surface of another, as seen in riser interference cases.

The line contact model supports relative axial motion between the contact lines. In addition, axial friction can be modelled. Line Contact Force results are available for lines that are in a line contact relationship.

This new line contact model is distinct from the previously existing line clashing model in OrcaFlex, which is still available.
Line Bending Hysteresis

The hysteretic bend stiffness model has been enhanced to allow modelling of lines in a depressurised state during statics. This is controlled by a new data item, Statics Model, set on the variable data form, that can be either Pressurised or Depressurised. The former results in the model used in previous versions of the program. The new Depressurised option results in a linear bending stiffness being used during statics. The bending stiffness is taken to be the slope of the final segment of the bend stiffness data (i.e. the slope determined by the final two rows of the data table). When dynamics starts, the program switches to the dynamic hysteresis model and ensures that the transition from statics (linear elastic) to dynamics (non-linear hysteretic) is continuous.
P-y Models

P-y models can now be applied to lines that are slightly off vertical. The undeformed configuration of the P-y springs is determined by the end orientation at the bottom end of the line. Previous versions of the program assumed that the undeformed configuration of the P-y springs was vertically upwards. This means that models built with previous versions of the program, that have a bottom end orientation that is not vertically upwards, will be interpreted differently by 9.6a and later. The program displays a warning message to this effect when you load such a model.
New results variables, P-y deflection and P-y resistance, have been added.
The implementation of the API RP 2A soft clay P-y model has been updated to use the tabular form presented in supplement 3 to the code. This does mean that version 9.6 will give different results from version 9.5 for P-y models that use the soft clay option.


  • Previous:NAPA 2016
  • Next:Below did not link the
  • Letters A B C D E F G H I J K L M N O P Q R S T U V W X Y Z TOP